Devil Spirit question

[link2113]

i was wondering when your devil spirit runs out after a month, do you only have a certain amount of time to extend it or can you choose to extend it whenever you want. Like do you still see it by your chars health? It just doesnt give the bonuses? Or do you not see it at all?

[Boiler]

you can choose when to renew it after it "dies" and the hp/mp bouns will be gone untill you renew it again.